Water

12 pages, 5080 KB

Open AccessArticle

Advanced Treatment of High-Concentration Ammonia–Nitrogen Wastewater by Pantothenic Acid-Enhanced Photosynthetic Bacteria

by Zhisong Bao, Haorui Li, Huajun Bao, Zhihe Chen, Yingyu Tan, Lei Qin and Tiejun Li

Water 2025, 17(14), 2166; https://doi.org/10.3390/w17142166 - 21 Jul 2025

Viewed by 557

Abstract

To address the slow growth rate of photosynthetic bacteria (PSB), this study introduces pantothenic acid as a biological enhancing factor. The effects of pantothenic acid on PSB proliferation and its effectiveness in treating high-concentration ammonia–nitrogen wastewater were systematically evaluated. Additionally, the effects of [...] Read more.

To address the slow growth rate of photosynthetic bacteria (PSB), this study introduces pantothenic acid as a biological enhancing factor. The effects of pantothenic acid on PSB proliferation and its effectiveness in treating high-concentration ammonia–nitrogen wastewater were systematically evaluated. Additionally, the effects of different culture conditions, including dark aeration, darkness, light exposure, and light aeration, on PSB growth were investigated. The results show that optimal PSB growth was achieved with 20 mg/L of pantothenic acid; however, higher concentrations of pantothenic acid inhibited bacterial growth. The addition of pantothenic acid also significantly enhanced the performance of PSB in treating high-concentration organic wastewater, increasing the removal rates of COD, ammonia nitrogen, total phosphorus, and total nitrogen to 43.0%, 94.0%, 49.7%, and 51.0%, respectively. Furthermore, a synergistic effect between dark aeration and light exposure was observed. When the time of light and dark aeration was set at 1:1, the highest PSB yield was recorded, and the removal efficiencies of COD, ammonia nitrogen, total nitrogen, and total phosphorus increased to 71.4%, 95.3%, 57.1%, and 74.7%, respectively. Through the introduction of pantothenic acid and optimization of culture mode, the rapid growth of PSB and highly efficient treatment of organic wastewater were achieved, providing a new approach for advanced wastewater treatment and resource utilization. Full article

(This article belongs to the Special Issue Wastewater Resourceization: Pioneering the Future of Sustainable Water)

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21 pages, 12252 KB

Open AccessArticle

Changes in Intra-Annual River Runoff in the Ile and Zhetysu Alatau Mountains Under Climate Change Conditions

by Rustam G. Abdrakhimov, Victor P. Blagovechshenskiy, Sandugash U. Ranova, Aigul N. Akzharkynova, Sezar Gülbaz, Ulzhan R. Aldabergen and Aidana N. Kamalbekova

Water 2025, 17(14), 2165; https://doi.org/10.3390/w17142165 - 21 Jul 2025

Viewed by 469

Abstract

This paper presents the results of studies on intra-annual runoff changes in the Ile River basin based on data from gauging stations up to 2021. Changes in climatic characteristics that determine runoff formation in the mountainous and foothill areas of the river catchment [...] Read more.

This paper presents the results of studies on intra-annual runoff changes in the Ile River basin based on data from gauging stations up to 2021. Changes in climatic characteristics that determine runoff formation in the mountainous and foothill areas of the river catchment have led to alterations in the water regime of the watercourses. The analysis of the temporal and spatial patterns of river flow formation in the basin, as well as its distribution by seasons and months, is essential for solving applied water management problems and assessing the risks of hazardous hydrological phenomena, such as high floods and low water levels. The statistical analysis of annual and monthly river runoff fluctuations enabled the identification of relatively homogeneous estimation periods during stationary observations under varying climatic conditions. The obtained characteristics of annual and intra-annual river runoff in the Ile River basin for the modern period provide insights into changes in average monthly water discharge and, more broadly, runoff volume during different phases of the water regime. In the future, these characteristics are expected to guide the design of hydraulic structures and the rational use of surface runoff in this intensively developing region of Kazakhstan. Full article

(This article belongs to the Section Water and Climate Change)

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18 pages, 2960 KB

Open AccessArticle

Early Leak and Burst Detection in Water Pipeline Networks Using Machine Learning Approaches

by Kiran Joseph, Jyoti Shetty, Rahul Patnaik, Noel S. Matthew, Rudi Van Staden, Wasantha P. Liyanage, Grant Powell, Nathan Bennett and Ashok K. Sharma

Water 2025, 17(14), 2164; https://doi.org/10.3390/w17142164 - 21 Jul 2025

Viewed by 873

Abstract

Leakages in water distribution networks pose a formidable challenge, often leading to substantial water wastage and escalating operational costs. Traditional methods for leak detection often fall short, particularly when dealing with complex or subtle data patterns. To address this, a comprehensive comparison of [...] Read more.

Leakages in water distribution networks pose a formidable challenge, often leading to substantial water wastage and escalating operational costs. Traditional methods for leak detection often fall short, particularly when dealing with complex or subtle data patterns. To address this, a comprehensive comparison of fourteen machine learning algorithms was conducted, with evaluation based on key performance metrics such as multi-class classification metrics, micro and macro averages, accuracy, precision, recall, and F1-score. The data, collected from an experimental site under leak, major leak, and no-leak scenarios, was used to perform multi-class classification. The results highlight the superiority of models such as Random Forest, K-Nearest Neighbours, and Decision Tree in detecting leaks with high accuracy and robustness. Multiple models effectively captured the nuances in the data and accurately predicted the presence of a leak, burst, or no leak, thus automating leak detection and contributing to water conservation efforts. This research demonstrates the practical benefits of applying machine learning models in water distribution systems, offering scalable solutions for real-time leak detection. Furthermore, it emphasises the role of machine learning in modernising infrastructure management, reducing water losses, and promoting the sustainability of water resources, while laying the groundwork for future advancements in predictive maintenance and resilience of water infrastructure. Full article

(This article belongs to the Special Issue Urban Water Resources: Sustainable Management and Policy Needs)

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19 pages, 4635 KB

Open AccessArticle

Prediction of Scouring Hole Morphology Induced by Underwater Jets Using CFD–DEM Simulation

by Yina Wang, Yang Wang, Jiachen Zhang, Jielong Hu, Zihao Duan and Qibo Zhang

Water 2025, 17(14), 2163; https://doi.org/10.3390/w17142163 - 21 Jul 2025

Viewed by 465

Abstract

Underwater jet scouring is an efficient, flexible underwater dredging technique, yet its complex physical mechanisms and dynamic evolution hinder dredging effectiveness evaluation. Existing studies mostly use empirical formulas and neglect the sediment properties’ influence on scour holes. This study integrates numerical simulation, theoretical [...] Read more.

Underwater jet scouring is an efficient, flexible underwater dredging technique, yet its complex physical mechanisms and dynamic evolution hinder dredging effectiveness evaluation. Existing studies mostly use empirical formulas and neglect the sediment properties’ influence on scour holes. This study integrates numerical simulation, theoretical derivation, and sediment characteristics to develop a universal model for efficiently predicting underwater jet scour hole morphology, overcoming existing models’ limitations of over-simplifying complex physics and insufficient experimental data alignment. Using CFD–DEM coupling to simulate scouring, it correlates key physical parameters (average/maximum shear rate, average/maximum shear velocity) with jet characteristics (nozzle diameter, velocity, distance) via theoretical derivation and simplifications, validated using multi-condition simulation data. Comparative analysis shows maximum relative errors of 13% for depth and 7% for width, confirming the engineering applicability in scour hole prediction. Full article

(This article belongs to the Section Hydraulics and Hydrodynamics)

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23 pages, 6048 KB

Open AccessArticle

Design and Implementation of a Hybrid Real-Time Salinity Intrusion Monitoring and Early Warning System for Bang Kachao, Thailand

by Uma Seeboonruang, Pinit Tanachaichoksirikun, Thanavit Anuwongpinit and Uba Sirikaew

Water 2025, 17(14), 2162; https://doi.org/10.3390/w17142162 - 21 Jul 2025

Viewed by 600

Abstract

Salinity intrusion is a growing threat to freshwater resources, particularly in low-lying coastal and estuarine regions, necessitating the development of effective early warning systems (EWS) to support timely mitigation. Although various water quality monitoring technologies exist, many face challenges related to long-term sustainability, [...] Read more.

Salinity intrusion is a growing threat to freshwater resources, particularly in low-lying coastal and estuarine regions, necessitating the development of effective early warning systems (EWS) to support timely mitigation. Although various water quality monitoring technologies exist, many face challenges related to long-term sustainability, ongoing maintenance, and accessibility for local users. This study introduces a novel hybrid real-time salinity intrusion early warning system that uniquely integrates fixed and portable monitoring technologies with strong community participation—an approach not yet widely applied in comparable urban-adjacent delta regions. Unlike traditional systems, this model emphasizes local ownership, flexible data collection, and system scalability in resource-constrained environments. This study presents a real-time salinity intrusion early warning system for Bang Kachao, Thailand, combining eight fixed monitoring stations and 20 portable salinity measurement devices. The system was developed in response to community needs, with local input guiding both station placement and the design of mobile measurement tools. By integrating fixed stations for continuous, high-resolution data collection with portable devices for flexible, on-demand monitoring, the system achieves comprehensive spatial coverage and adaptability. A core innovation lies in its emphasis on community participation, enabling villagers to actively engage in monitoring and decision-making. The use of IoT-based sensors, Remote Telemetry Units (RTUs), and cloud-based data platforms further enhances system reliability, efficiency, and accessibility. Automated alerts are issued when salinity thresholds are exceeded, supporting timely interventions. Field deployment and testing over a seven-month period confirmed the system’s effectiveness, with fixed stations achieving 90.5% accuracy and portable devices 88.7% accuracy in detecting salinity intrusions. These results underscore the feasibility and value of a hybrid, community-driven monitoring approach for protecting freshwater resources and building local resilience in vulnerable regions. Full article

(This article belongs to the Section New Sensors, New Technologies and Machine Learning in Water Sciences)

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12 pages, 7046 KB

Open AccessArticle

Cu–Co–O-Codoped Graphite Carbon Nitride as an Efficient Peroxymonosulfate Activator for Sulfamethoxazole Degradation: Characterization, Performance, and Mechanism

by Qiliang Xiao and Jun Nan

Water 2025, 17(14), 2161; https://doi.org/10.3390/w17142161 - 21 Jul 2025

Viewed by 442

Abstract

This study presents the development of a novel Cu–Co–O-codoped graphitic carbon nitride (g-C₃N₄) catalyst for efficient peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX) in aqueous environments. The synthesized Cu–Co–O-g-C₃N₄ catalyst demonstrated exceptional catalytic performance, achieving 90% [...] Read more.

This study presents the development of a novel Cu–Co–O-codoped graphitic carbon nitride (g-C₃N₄) catalyst for efficient peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX) in aqueous environments. The synthesized Cu–Co–O-g-C₃N₄ catalyst demonstrated exceptional catalytic performance, achieving 90% SMX removal within 10 min—significantly outperforming pristine g-C₃N₄ (14%) and O-doped g-C₃N₄ (22%)—with a reaction rate constant of 0.63 min⁻¹. The superior activity was attributed to the synergistic effects of Cu-Co bimetallic doping and oxygen incorporation, which enhanced the active sites, stabilized metal ions, and minimized leaching. Mechanistic studies revealed a dual-pathway degradation process: (1) a radical pathway dominated by sulfate radicals (SO₄•⁻) and (2) a non-radical pathway driven by singlet oxygen (¹O₂), with the latter identified as the dominant species through quenching experiments. The catalyst exhibited broad pH adaptability and optimal performance at neutral to alkaline conditions. Characterization techniques (XRD, FTIR, XPS) confirmed successful doping and revealed that oxygen incorporation modified the electronic structure of g-C₃N₄, improving charge carrier separation. This work provides a sustainable strategy for antibiotic removal, addressing key challenges in advanced oxidation processes (AOPs), and highlights the potential of multi-heteroatom-doped carbon nitride catalysts for water purification. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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24 pages, 8305 KB

Open AccessArticle

Development of Open-Source Tools for Event-Based Hydrological Modelling Using GIS and Python

by Andrés F. Almeida-Ñauñay, Ernesto Sanz, Antonio Berlanga, Miguel Ángel Patricio, José M. Molina and Sergio Zubelzu

Water 2025, 17(14), 2160; https://doi.org/10.3390/w17142160 - 21 Jul 2025

Viewed by 405

Abstract

Detailed modelling of water dynamics at the catchment is of paramount importance for the optimal management and allocation of water resources. The main objective of this work is to present a set of QGIS-based routines for processing easily available geographical information to deliver [...] Read more.

Detailed modelling of water dynamics at the catchment is of paramount importance for the optimal management and allocation of water resources. The main objective of this work is to present a set of QGIS-based routines for processing easily available geographical information to deliver inputs for integration into hydrological models developed in the Python environment. We present QGIS processes that deliver open format exchangeable files with physical information required for hydrological modelling, allowing a better tailoring of hydrological modelling tasks compared to other blinded existing models. We present the general framework by processing spatial information and running a set of hydrological models in different cases studies in the Spanish Ebro River basin, proving the utility of the proposed method for applying complex and tailored hydrological simulations. Full article

(This article belongs to the Section Hydrology)

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31 pages, 7304 KB

Open AccessArticle

Integrating Groundwater Modelling for Optimized Managed Aquifer Recharge Strategies

by Ghulam Zakir-Hassan, Jehangir F. Punthakey, Catherine Allan and Lee Baumgartner

Water 2025, 17(14), 2159; https://doi.org/10.3390/w17142159 - 20 Jul 2025

Viewed by 669

Abstract

Managed aquifer recharge (MAR) is a complex and hidden process of storing surplus water under the ground surface and extracting it as, when and where needed. Evaluation of the success of any MAR project is challenging due to uncertainty in estimating the hydrogeological [...] Read more.

Managed aquifer recharge (MAR) is a complex and hidden process of storing surplus water under the ground surface and extracting it as, when and where needed. Evaluation of the success of any MAR project is challenging due to uncertainty in estimating the hydrogeological characteristics of the subsurface media. This paper demonstrates the use of a groundwater model (MODFLOW) to evaluate a new, large-scale regional MAR project in the agricultural heartland in Punjab, Pakistan. In this MAR project, flood waters have been diverted to the bed of an abandoned canal, where 144 recharge wells (the wells for accelerating the recharge into the aquifer) have been constructed to accelerate the recharge to the aquifer. The model was calibrated for a period of five years from October 2015 to June 2020 on a monthly stress period and the resulting water levels were simulated till 2035. The water balance components and future response of the aquifer to different scenarios up to 2035 including with and without MAR situations are presented. The model simulations showed that MAR can contribute to the replenishment of the aquifer and its potential for the case study site to contribute significantly to the management of groundwater and to enhance supplies for intensive agriculture. It was further established that MODFLOW can help in the evaluation of effectiveness of a MAR scheme. This study is unique as it evaluates a significantly large MAR project in an area where this practice has not been developed for improving groundwater access for large scale irrigation. The model provides guidelines for decision makers in the region as well as for the global community and livelihood benefits for rural communities. Full article

(This article belongs to the Special Issue Advances in Surface Water and Groundwater Simulation in River Basin)

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19 pages, 4307 KB

Open AccessArticle

A Scalable Machine Learning Framework for Hydrological Water Quality Monitoring Using Physicochemical and Microbial Parameters

by Priyam Nath Bhowmik, Kezia Saini, Nunna Tagore Sai Priya, Pradyut Anand and Bayram Ateş

Water 2025, 17(14), 2158; https://doi.org/10.3390/w17142158 - 20 Jul 2025

Viewed by 644

Abstract

Monitoring river water quality is essential for environmental sustainability and public health. This study proposes a machine learning (ML)-based framework to model, predict, and classify the Water Quality Index (WQI) using river water samples collected across India. The dataset includes eight physicochemical and [...] Read more.

Monitoring river water quality is essential for environmental sustainability and public health. This study proposes a machine learning (ML)-based framework to model, predict, and classify the Water Quality Index (WQI) using river water samples collected across India. The dataset includes eight physicochemical and microbial parameters: Temperature, pH, Dissolved Oxygen, Biological Oxygen Demand (BOD), Conductivity, Nitrate/Nitrite, Fecal Coliform, and Total Coliform. The WQI was calculated using weighted aggregation and categorized into Excellent, Good, Medium, and Poor classes. Regression and classification models—such as Linear Regression, Random Forest, Gradient Boosting, and Logistic Regression—were evaluated using MAE, RMSE, R², Accuracy, Precision, Recall, and F1-score. Spatial mapping and exploratory data analysis were conducted to identify regional patterns. Feature importance (Gini and permutation-based) and error analysis enhanced interpretability. The framework achieved over 95% agreement with manual WQI classification, highlighting its effectiveness for real-time, scalable water quality monitoring and policy support. Full article

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17 pages, 9043 KB

Open AccessArticle

Soil Erosion Dynamics and Driving Force Identification in the Yiluo River Basin Under Multiple Future Scenarios

by Jun Hou, Jianwei Wang, Xiaofeng Chen, Yong Hu and Guoqiang Dong

Water 2025, 17(14), 2157; https://doi.org/10.3390/w17142157 - 20 Jul 2025

Viewed by 359

Abstract

Our study focused on identifying the evolution of soil erosion and its key drivers under multiple future scenarios in the Yiluo River Basin. Integrating the Universal Soil Loss Equation (USLE), future land use and vegetation cover simulation methods, and the Geodetector model, we [...] Read more.

Our study focused on identifying the evolution of soil erosion and its key drivers under multiple future scenarios in the Yiluo River Basin. Integrating the Universal Soil Loss Equation (USLE), future land use and vegetation cover simulation methods, and the Geodetector model, we analyzed historical soil erosion trends (2000–2020), projected future soil erosion risks under multiple Shared Socioeconomic Pathways (SSPs), and quantified the interactive effects of key driving factors. The results showed that soil erosion within the basin exhibited moderate intensity. Over the past 20 years, soil erosion decreased by 28.78%, with 76.29% of the area experiencing reduced erosion intensity. Future projections indicated an overall declining trend in soil erosion, showing reductions of 4.93–35.95% compared to baseline levels. However, heterogeneous patterns emerged across various scenarios, with the highest risk observed under SSP585. Land use type was identified as the core driving factor behind soil erosion (explanatory capacity q-value > 5%). Under diverse future climate scenarios, interactions between land use type and precipitation and temperature exhibited high sensitivity, highlighting the critical regulatory role of climate change in regulating erosion processes. This research provides a scientific foundation for the precise prevention and adaptive management of soil erosion in the Loess Plateau region. Full article

(This article belongs to the Special Issue Yellow River Basin Management under Pressure: Present State, Restoration and Protection III)

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16 pages, 4304 KB

Open AccessFeature PaperArticle

Numerical Study of Turbulent Open-Channel Flow Through Submerged Rigid Vegetation

by Theodora P. Kalaryti, Nikolaos Th. Fourniotis and Efstratios E. Tzirtzilakis

Water 2025, 17(14), 2156; https://doi.org/10.3390/w17142156 - 20 Jul 2025

Viewed by 421

Abstract

In the present study, three-dimensional turbulent, subcritical open-channel flow (Fr = 0.19) through submerged rigid vegetation is numerically investigated using the ANSYS FLUENT solver (v. 22. 1). The Volume of Fluid (VOF) method is applied for free-surface tracking, while the standard k-ε [...] Read more.

In the present study, three-dimensional turbulent, subcritical open-channel flow (Fr = 0.19) through submerged rigid vegetation is numerically investigated using the ANSYS FLUENT solver (v. 22. 1). The Volume of Fluid (VOF) method is applied for free-surface tracking, while the standard k-ε turbulence model is employed for turbulence closure. Vegetation is modeled as vertical rigid cylinders fixed at the bottom of the channel. Regarding the arrangement of the stems, two cases are examined. In the first case, a linear arrangement of three equally spaced vegetative stems is located transversely at the center of the channel, while in the second case, a parallel arrangement of fifteen equidistant vegetative stems is located downstream of the channel center. In both cases, the vertical velocity profile within the submerged vegetation layer deviates significantly from that of the upper non-vegetated layer, which generally adheres to the logarithmic velocity distribution. In the second case, flow field repeatability is observed after the third stem series, particularly in terms of velocity profiles. Additionally, the structure of turbulence is noticeably affected in the vicinity of the stems, resulting in higher eddy viscosity values near each stem’s crest area. Furthermore, a localized drop in the free surface is recorded above the vegetated region, while a slight rise is observed upstream of each stem series, consistent with subcritical open-channel flow. Full article

(This article belongs to the Special Issue Recent Advances in Hydraulics Engineering)

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32 pages, 6735 KB

Open AccessArticle

Flood Hazard Assessment Through AHP, Fuzzy AHP, and Frequency Ratio Methods: A Comparative Analysis

by Nikoleta Taoukidou, Dimitrios Karpouzos and Pantazis Georgiou

Water 2025, 17(14), 2155; https://doi.org/10.3390/w17142155 - 19 Jul 2025

Viewed by 634

Abstract

Floods are the biggest hydrometeorological disaster, affecting millions annually. Thus, flood hazard assessment is crucial and plays a pivotal role in rational water management. This study was undertaken to evaluate flood hazards through the application of MCDM methods and a bivariate statistical model [...] Read more.

Floods are the biggest hydrometeorological disaster, affecting millions annually. Thus, flood hazard assessment is crucial and plays a pivotal role in rational water management. This study was undertaken to evaluate flood hazards through the application of MCDM methods and a bivariate statistical model integrated with GIS. The methodologies applied were AHP, fuzzy AHP, and the frequency ratio. Eight flood-related criteria were considered—elevation, flow accumulation, geology, slope, land use/land cover (LULC), distance from the drainage network, drainage density, and rainfall index—for the construction of a Flood Hazard Map for each methodology, with the aim to delineate the regions within the study area most prone to flooding. The results demonstrated that around 34% of the Chalkidiki regional unit presents a high and very high hazard to the occurrence of floods. The comparison of the maps generated using DSC demonstrated that all models are capable of delineating high and very high hazard areas with overlap values varying from 0.8 to 0.98. The validation results indicated that the models exhibit sufficient performance in flood hazard mapping with AUC-ROC scores of 66.6%, 65.7%, and 76.5% for the AHP, FAHP, and FR models, respectively. Full article

(This article belongs to the Special Issue Machine Learning Models for Flood Hazard Assessment)

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16 pages, 3780 KB

Open AccessArticle

Cascade Reservoir Outflow Simulation Based on Physics-Constrained Random Forest

by Zehui Zhou, Lei Yu, Yu Zhang, Benyou Jia, Luchen Zhang and Shaoze Luo

Water 2025, 17(14), 2154; https://doi.org/10.3390/w17142154 - 19 Jul 2025

Viewed by 353

Abstract

Accurate reservoir outflow simulation is crucial for water resource management. However, traditional machine learning-based simulation methods have not sufficiently considered the physical constraints of reservoir operation, which may lead to unrealistic issues such as negative outflows or water levels exceeding the reservoir’s own [...] Read more.

Accurate reservoir outflow simulation is crucial for water resource management. However, traditional machine learning-based simulation methods have not sufficiently considered the physical constraints of reservoir operation, which may lead to unrealistic issues such as negative outflows or water levels exceeding the reservoir’s own limitations. This study integrates physical constraints into the random forest (RF) model using the Sigmoid function, constructing a physics-constrained random forest model (PC-RF) for cascade reservoir outflow simulation. A stratified sampling strategy based on hydrological year types is used to create the training and validation datasets. The coefficient of determination (R²) and root mean square error (RMSE) are used to evaluate the model’s performance for medium- to long-term predictions of reservoir outflows on a 10-day time scale. Additionally, the mean decrease in impurity method is used to assess the importance of input features, thereby enhancing the model’s interpretability. The application the Yalong River cascade reservoir indicates that (1) compared to traditional RF, the PC-RF achieved significant breakthroughs, with an increase of 37.13% in the R² and a decrease of 60.04% in the RMSE when simulating outflows from the Lianghekou Reservoir, with all reservoirs maintaining an R² above 0.95, with no instances of unrealistic outcomes; (2) PC-RF effectively integrated historical operational patterns with top three features being previous period outflow, current inflow, and previous period inflow, providing interpretable insights for operational decision-making. The PC-RF model demonstrates high accuracy and practical potential in cascade reservoir outflow simulation, providing valuable applications for cascade reservoir management and water resource optimization. Full article

(This article belongs to the Special Issue Advances in Surface Water and Groundwater Simulation in River Basin)

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21 pages, 842 KB

Open AccessArticle

A Fresh Perspective on Freshwater Data Management and Sharing: Exploring Insights from the Technology Sector

by Jess Kidd, Nathanael T. Bergbusch, Graham Epstein, Geoffrey Gunn, Heidi Swanson and Simon C. Courtenay

Water 2025, 17(14), 2153; https://doi.org/10.3390/w17142153 - 19 Jul 2025

Viewed by 390

Abstract

It is well established that effective management and restoration of freshwater ecosystems is often limited by the availability of reusable data. Although numerous public, private, and nonprofit organizations collect data from freshwater ecosystems, much of what is collected remains inaccessible or unusable by [...] Read more.

It is well established that effective management and restoration of freshwater ecosystems is often limited by the availability of reusable data. Although numerous public, private, and nonprofit organizations collect data from freshwater ecosystems, much of what is collected remains inaccessible or unusable by Rights holders and end users (including researchers, practitioners, community members, and decision-makers). In Canada, the federal government plans to improve freshwater data sharing practices through the newly formed Canada Water Agency, which is currently drafting a National Freshwater Data Strategy. Our study aimed to support these efforts by synthesizing insights from the technology sector, where data management and sharing practices are more mature. We interviewed 12 experts from the technology sector, asking them for advice on how to improve data sharing practices in the freshwater science sector. Using a Reflexive Thematic Analysis of participants’ responses to semi-structured interview questions, we identified nine broad recommendations. Recommendations centred on motivating open data sharing, promoting data reuse through data licences, training and skill building, and developing standards and digital solutions that enable data discovery, accessibility, interoperability, and reuse. These recommendations can support the numerous initiatives that are working to improve access to high-quality freshwater data and help address the pressing crisis of global freshwater ecosystem degradation. Full article

(This article belongs to the Section Biodiversity and Functionality of Aquatic Ecosystems)

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20 pages, 2143 KB

Open AccessArticle

Bioadsorption of Manganese with Modified Orange Peel in Aqueous Solution: Box–Behnken Design Optimization and Adsorption Isotherm

by Liz Marzano-Vasquez, Giselle Torres-López, Máximo Baca-Neglia, Wilmer Chávez-Sánchez, Roberto Solís-Farfán, José Curay-Tribeño, César Rodríguez-Aburto, Alex Vallejos-Zuta, Jesús Vara-Sanchez, César Madueño-Sulca, Cecilia Rios-Varillas de Oscanoa and Alex Pilco-Nuñez

Water 2025, 17(14), 2152; https://doi.org/10.3390/w17142152 - 19 Jul 2025

Viewed by 571

Abstract

Chemically demethoxylated and Ca-cross-linked orange-peel waste was engineered as a biosorbent for Mn(II) removal from water. A three-factor Box–Behnken design (biosorbent dose 3–10 g L⁻¹, initial Mn²⁺ 100–300 mg L⁻¹, contact time 3–8 h; pH 5.5 ± 0.1, [...] Read more.

Chemically demethoxylated and Ca-cross-linked orange-peel waste was engineered as a biosorbent for Mn(II) removal from water. A three-factor Box–Behnken design (biosorbent dose 3–10 g L⁻¹, initial Mn²⁺ 100–300 mg L⁻¹, contact time 3–8 h; pH 5.5 ± 0.1, 25 °C) required only 16 runs to locate the optimum (10 g L⁻¹, 100 mg L⁻¹, 8 h), at which the material removed 94.8% ± 0.3% manganese removal under the optimized conditions (10 g L⁻¹, 100 mg L⁻¹, 8 h, pH 5.5) of dissolved manganese and reached a Langmuir capacity of 29.7 mg g⁻¹. Equilibrium data fitted the Freundlich (R² = 0.968) and Sips (R² = 0.969) models best, indicating a heterogeneous surface, whereas kinetic screening confirmed equilibrium within 6 h. FTIR and SEM–EDX verified abundant surface –COO⁻/–OH groups and showed Mn deposits that partially replaced residual Ca, supporting an ion-exchange component in the uptake mechanism. A preliminary cost analysis (<USD 10 kg⁻¹) and > 90% regeneration efficiency over three cycles highlight the economic and environmental promise of this modified agro-waste for polishing Mn-laden effluents. Full article

(This article belongs to the Special Issue Advances in Metal Removal and Recovery from Water)

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34 pages, 9311 KB

Open AccessArticle

Historical Evolution and Future Trends of Riverbed Dynamics Under Anthropogenic Impact and Climatic Change: A Case Study of the Ialomița River (Romania)

by Andrei Radu and Laura Comănescu

Water 2025, 17(14), 2151; https://doi.org/10.3390/w17142151 - 19 Jul 2025

Viewed by 917

Abstract

Riverbed dynamics are natural processes that are strongly driven by human and climatic factors. In the last two centuries, the anthropogenic influence and impact of climate change on European rivers has resulted in significant degradation of riverbeds. This research paper aims to determine [...] Read more.

Riverbed dynamics are natural processes that are strongly driven by human and climatic factors. In the last two centuries, the anthropogenic influence and impact of climate change on European rivers has resulted in significant degradation of riverbeds. This research paper aims to determine the historical evolution (1856–2021) and future trends of the Ialomița riverbed (Romania) under the influence of anthropogenic impact and climate change. The case study is a reach of 66 km between the confluences with the Ialomicioara and Pâscov rivers. The localisation in a contact zone between the Curvature Subcarpathians and the Târgoviște Plain, the active recent tectonic uplift of the area, and the intense anthropogenic intervention gives to this river reach favourable conditions for pronounced riverbed dynamics over time. To achieve the aim of the study, we developed a complex methodology which involves the use of Geographical Information System (GIS) techniques, hierarchical cluster analysis (HCA), the Mann–Kendall test (MK), and R programming. The results indicate that the evolution of the Ialomița River aligns with the general trends observed across Europe and within Romania, characterised by a reduction in riverbed geomorphological complexity and a general transition from a braided, multi-thread into a sinuous, single-thread fluvial style. The main processes consist of channel narrowing and incision alternating with intense meandering. However, specific temporal and spatial evolution patterns were identified, mainly influenced by the increasingly anthropogenic local influences and confirmed climate changes in the study area since the second half of the 20th century. Future evolutionary trends suggest that, in the absence of river restoration interventions, the Ialomița riverbed is expected to continue degrading on a short-term horizon, following both climatic and anthropogenic signals. The findings of this study may contribute to a better understanding of recent river behaviours and serve as a valuable tool for the management of the Ialomița River. Full article

(This article belongs to the Special Issue Climate Change and Hydrological Processes, 2nd Edition)

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25 pages, 16639 KB

Open AccessArticle

Hydraulic Modeling of Newtonian and Non-Newtonian Debris Flows in Alluvial Fans: A Case Study in the Peruvian Andes

by David Chacon Lima, Alan Huarca Pulcha, Milagros Torrejon Llamoca, Guillermo Yorel Noriega Aquise and Alain Jorge Espinoza Vigil

Water 2025, 17(14), 2150; https://doi.org/10.3390/w17142150 - 19 Jul 2025

Viewed by 924

Abstract

Non-Newtonian debris flows represent a critical challenge for hydraulic infrastructure in mountainous regions, often causing significant damage and service disruption. However, current models typically simplify these flows as Newtonian, leading to inaccurate design assumptions. This study addresses this gap by comparing the hydraulic [...] Read more.

Non-Newtonian debris flows represent a critical challenge for hydraulic infrastructure in mountainous regions, often causing significant damage and service disruption. However, current models typically simplify these flows as Newtonian, leading to inaccurate design assumptions. This study addresses this gap by comparing the hydraulic behavior of Newtonian and non-Newtonian flows in an alluvial fan, using the Amoray Gully in Apurímac, Peru, as a case study. This gully intersects the Interoceánica Sur national highway via a low-water crossing (baden), making it a relevant site for evaluating debris flow impacts on critical road infrastructure. The methodology integrates hydrological analysis, rheological characterization, and hydraulic modeling. QGIS 3.16 was used for watershed delineation and extraction of physiographic parameters, while a high-resolution topographic survey was conducted using an RTK drone. Rainfall-runoff modeling was performed in HEC-HMS 4.7 using 25 years of precipitation data, and hydraulic simulations were executed in HEC-RAS 6.6, incorporating rheological parameters and calibrated with the footprint of a historical event (5-year return period). Results show that traditional Newtonian models underestimate flow depth by 17% and overestimate velocity by 54%, primarily due to unaccounted particle-collision effects. Based on these findings, a multi-barrel circular culvert was designed to improve debris flow management. This study provides a replicable modeling framework for debris-prone watersheds and contributes to improving design standards in complex terrain. The proposed methodology and findings offer practical guidance for hydraulic design in mountainous terrain affected by debris flows, especially where infrastructure intersects active alluvial fans. Full article

(This article belongs to the Topic Natural Hazards and Disaster Risks Reduction, 2nd Edition)

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18 pages, 1768 KB

Open AccessArticle

Comparative Risk Assessment of Legionella spp. Colonization in Water Distribution Systems Across Hotels, Passenger Ships, and Healthcare Facilities During the COVID-19 Era

by Antonios Papadakis, Eleftherios Koufakis, Elias Ath Chaidoutis, Dimosthenis Chochlakis and Anna Psaroulaki

Water 2025, 17(14), 2149; https://doi.org/10.3390/w17142149 - 19 Jul 2025

Viewed by 1520

Abstract

The colonization of Legionella spp. in engineered water systems constitutes a major public health threat. In this study, a six-year environmental surveillance (2020–2025) of Legionella colonization in five different types of facilities in Crete, Greece is presented, including hotels, passenger ships, primary healthcare [...] Read more.

The colonization of Legionella spp. in engineered water systems constitutes a major public health threat. In this study, a six-year environmental surveillance (2020–2025) of Legionella colonization in five different types of facilities in Crete, Greece is presented, including hotels, passenger ships, primary healthcare facilities, public hospitals, and private clinics. A total of 1081 water samples were collected and analyzed, and the overall positivity was calculated using culture-based methods. Only 16.46% of the samples exceeded the regulatory limit (>10³ CFU/L) in the total sample, with 44.59% overall Legionella positivity. Colonization by facility category showed the highest rates in primary healthcare facilities with 85.96%, followed by public hospitals (46.36%), passenger ships with 36.93%, hotels with 38.08%, and finally private clinics (21.42%). The association of environmental risk factors with Legionella positivity revealed a strong effect at hot water temperatures < 50 °C (RR = 2.05) and free chlorine residuals < 0.2 mg/L (RR = 2.22) (p < 0.0001). Serotyping analysis revealed the overall dominance of Serogroups 2–15 of L. pneumophila; nevertheless, Serogroup 1 was particularly prevalent in hospitals, passenger ships, and hotels. Based on these findings, the requirement for continuous environmental monitoring and risk management plans with preventive thermochemical controls tailored to each facility is highlighted. Finally, operational disruptions, such as those experienced during the COVID-19 pandemic, especially in primary care facilities and marine systems, require special attention. Full article

(This article belongs to the Special Issue Legionella: A Key Organism in Water Management)

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14 pages, 1835 KB

Open AccessArticle

Enhanced Nematode Reduction in Drinking Water Using Sodium Hypochlorite and Ozone

by Bojan Đurin, Ebrahim Alamatian, Mahmood Ramezani, Sara Dadar and Domagoj Nakić

Water 2025, 17(14), 2148; https://doi.org/10.3390/w17142148 - 18 Jul 2025

Viewed by 467

Abstract

Nematodes are among the organisms found in treated water. While generally considered harmless to human health, under certain conditions, they may serve as vectors for pathogenic viruses and bacteria, posing potential risks. Conventional disinfection processes in water treatment can contribute to the inactivation [...] Read more.

Nematodes are among the organisms found in treated water. While generally considered harmless to human health, under certain conditions, they may serve as vectors for pathogenic viruses and bacteria, posing potential risks. Conventional disinfection processes in water treatment can contribute to the inactivation or removal of nematodes, but their effectiveness varies. This study, conducted at a water treatment plant (WTP) in Mashhad, Iran, aimed to determine the optimal dose and contact time of sodium hypochlorite and ozone for enhancing nematode inactivation in the affected surface water. This research combined primary disinfection using sodium hypochlorite at the existing WTP with a pilot ozone injection system to evaluate their individual and combined effectiveness. The results show that sodium hypochlorite at a concentration of 2 mg/L achieved 68% nematode inactivation. At 2.0 mg/L, with a 20 min contact time, ozone disinfection resulted in 39% inactivation. However, the combined application of sodium hypochlorite and ozone significantly improved efficiency, reaching 92% nematode inactivation when sodium hypochlorite and ozone were applied at 2 mg/L and 3 mg/L, respectively, with a 20 min ozone contact time. These findings indicate that, among the disinfection methods examined, the combined use of sodium hypochlorite and ozone is the most effective approach for nematode inactivation in drinking water, offering a promising strategy for improving water quality and safety. Full article

(This article belongs to the Section Water Quality and Contamination)

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16 pages, 2559 KB

Open AccessArticle

Microbead-Mediated Enhancement of Bacterial Toxicity: Oxidative Stress and Apoptosis in Korean Rockfish, Sebastes schlegeli, Following Exposure to Streptococcus iniae

by Young Hoon Kwon, Jin A. Kim, Young-Su Park, Jun-Hwan Kim and Cheol Young Choi

Water 2025, 17(14), 2147; https://doi.org/10.3390/w17142147 - 18 Jul 2025

Viewed by 370

Abstract

Korean rockfish, Sebastes schlegeli, a coastal species, is vulnerable to pollutants such as microplastics and bacteria. While interactions between microplastics and other pollutants have been studied, little is known about microplastic and bacteria interactions. This study examined the effects of combined exposure [...] Read more.

Korean rockfish, Sebastes schlegeli, a coastal species, is vulnerable to pollutants such as microplastics and bacteria. While interactions between microplastics and other pollutants have been studied, little is known about microplastic and bacteria interactions. This study examined the effects of combined exposure to polystyrene microplastics in the form of microbeads (MB; 0.2 µm, 5 and 50 beads/L) and Streptococcus iniae (1 × 10⁵ and 1 × 10⁷ CFU/mL) for five days on oxidative stress and apoptosis in Korean rockfish. We assessed the mRNA expression and activity of oxidative stress markers (SOD, CAT, H₂O₂, NO, CYP1A1, GST), plasma LPO levels, and caspase-3 expression in liver tissue. Co-exposure to high MB and S. iniae concentrations significantly elevated oxidative stress and apoptosis markers, suggesting enhanced toxicity. This may result from MB facilitating pathogen transport into the fish, indicating microplastics can act as vectors for bacterial infection in aquatic environments. Full article

(This article belongs to the Special Issue Advances in Plastic’s (Eco)Toxicity Research in the Aquatic and Terrestrial Environments)

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18 pages, 11666 KB

Open AccessArticle

A Hybrid XAJ-LSTM-TFM Model for Improved Runoff Simulation in the Poyang Lake Basin: Integrating Physical Processes with Temporal and Lag Feature Learning

by Haoyu Jiang and Chunxiao Zhang

Water 2025, 17(14), 2146; https://doi.org/10.3390/w17142146 - 18 Jul 2025

Viewed by 494

Abstract

As the largest freshwater lake in China, Poyang Lake plays a crucial role in hydrological processes. Conventional models often fail to capture the time-lagged relationships between meteorological drivers and runoff responses, while lacking regional generalization capability. To address these limitations, this study proposes [...] Read more.

As the largest freshwater lake in China, Poyang Lake plays a crucial role in hydrological processes. Conventional models often fail to capture the time-lagged relationships between meteorological drivers and runoff responses, while lacking regional generalization capability. To address these limitations, this study proposes a novel XAJ-LSTM-TFM hybrid model that accounts for time-lagged hydrological responses and enhances the regional applicability of the Xinanjiang model. The model innovatively integrates the physical mechanisms of the Xinanjiang model with the temporal learning capacity of LSTM networks. By incorporating intermediate hydrological variables (including interflow and groundwater flow) along with 1–3 day lagged meteorological features, the model achieves an average 15.3% improvement in Nash–Sutcliffe Efficiency (NSE) across five sub-basins, with the Ganjiang Basin attaining an NSE of 0.812 and a 25.7% reduction in flood peak errors. The results demonstrate superior runoff simulation performance and reliable generalization capability under intensive anthropogenic activities. Full article

(This article belongs to the Special Issue Water Modeling Using Combined Machine Learning and Fieldwork Investigation)

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19 pages, 1167 KB

Open AccessArticle

A Reservoir Group Flood Control Operation Decision-Making Risk Analysis Model Considering Indicator and Weight Uncertainties

by Tangsong Luo, Xiaofeng Sun, Hailong Zhou, Yueping Xu and Yu Zhang

Water 2025, 17(14), 2145; https://doi.org/10.3390/w17142145 - 18 Jul 2025

Viewed by 325

Abstract

Reservoir group flood control scheduling decision-making faces multiple uncertainties, such as dynamic fluctuations of evaluation indicators and conflicts in weight assignment. This study proposes a risk analysis model for the decision-making process: capturing the temporal uncertainties of flood control indicators (such as reservoir [...] Read more.

Reservoir group flood control scheduling decision-making faces multiple uncertainties, such as dynamic fluctuations of evaluation indicators and conflicts in weight assignment. This study proposes a risk analysis model for the decision-making process: capturing the temporal uncertainties of flood control indicators (such as reservoir maximum water level and downstream control section flow) through the Long Short-Term Memory (LSTM) network, constructing a feasible weight space including four scenarios (unique fixed value, uniform distribution, etc.), resolving conflicts among the weight results from four methods (Analytic Hierarchy Process (AHP), Entropy Weight, Criteria Importance Through Intercriteria Correlation (CRITIC), Principal Component Analysis (PCA)) using game theory, defining decision-making risk as the probability that the actual safety level fails to reach the evaluation threshold, and quantifying risks based on the First-Order Second-Moment (FOSM) method. Case verification in the cascade reservoirs of the Qiantang River Basin of China shows that the model provides a risk assessment framework integrating multi-source uncertainties for flood control scheduling decisions through probabilistic description of indicator uncertainties (e.g., Zmax1 with μ = 65.3 and σ = 8.5) and definition of weight feasible regions (99% weight distribution covered by the 3σ criterion), filling the methodological gap in risk quantification during the decision-making process in existing research. Full article

(This article belongs to the Special Issue Flood Risk Identification and Management, 2nd Edition)

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31 pages, 9878 KB

Open AccessArticle

Shallow Sliding Failure of Slope Induced by Rainfall in Highly Expansive Soils Based on Model Test

by Shuangping Li, Bin Zhang, Shanxiong Chen, Zuqiang Liu, Junxing Zheng, Min Zhao and Lin Gao

Water 2025, 17(14), 2144; https://doi.org/10.3390/w17142144 - 18 Jul 2025

Viewed by 330

Abstract

Expansive soils, characterized by the presence of surface and subsurface cracks, over-consolidation, and swell-shrink properties, present significant challenges to slope stability in geotechnical engineering. Despite extensive research, preventing geohazards associated with expansive soils remains unresolved. This study investigates shallow sliding failures in slopes [...] Read more.

Expansive soils, characterized by the presence of surface and subsurface cracks, over-consolidation, and swell-shrink properties, present significant challenges to slope stability in geotechnical engineering. Despite extensive research, preventing geohazards associated with expansive soils remains unresolved. This study investigates shallow sliding failures in slopes of highly expansive soils induced by rainfall, using model tests to explore deformation and mechanical behavior under cyclic wetting and drying conditions, focusing on the interaction between soil properties and environmental factors. Model tests were conducted in a wedge-shaped box filled with Nanyang expansive clay from Henan, China, which is classified as high-plasticity clay (CH) according to the Unified Soil Classification System (USCS). The soil was compacted in four layers to maintain a 1:2 slope ratio (i.e., 1 vertical to 2 horizontal), which reflects typical expansive soil slope configurations observed in the field. Monitoring devices, including moisture sensors, pressure transducers, and displacement sensors, recorded changes in soil moisture, stress, and deformation. A static treatment phase allowed natural crack development to simulate real-world conditions. Key findings revealed that shear failure propagated along pre-existing cracks and weak structural discontinuities, supporting the progressive failure theory in shallow sliding. Cracks significantly influenced water infiltration, creating localized stress concentrations and deformation. Atmospheric conditions and wet-dry cycles were crucial, as increased moisture content reduced soil suction and weakened the slope’s strength. These results enhance understanding of expansive soil slope failure mechanisms and provide a theoretical foundation for developing improved stabilization techniques. Full article

(This article belongs to the Topic Hydraulic Engineering and Modelling)

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22 pages, 7529 KB

Open AccessArticle

Analysis of Human Health Risk Related to the Exposure of Arsenic Concentrations and Temporal Variation in Groundwater of a Semi-Arid Region in Mexico

by Jennifer Ortiz Letechipia, Miguel Eduardo Pinedo Vega, Julián González Trinidad, Hugo Enrique Júnez-Ferreira, Ana Isabel Veyna Gómez, Ada Rebeca Contreras Rodríguez, Cruz Octavio Robles Rovelo and Sandra Dávila Hernández

Water 2025, 17(14), 2143; https://doi.org/10.3390/w17142143 - 18 Jul 2025

Viewed by 383

Abstract

This study evaluates the human health risks associated with exposure to arsenic in groundwater from a semi-arid region of Mexico, focusing on concentration levels and their temporal variation. Arsenic concentrations were analyzed using ordinary kriging for spatial interpolation, along with descriptive and inferential [...] Read more.

This study evaluates the human health risks associated with exposure to arsenic in groundwater from a semi-arid region of Mexico, focusing on concentration levels and their temporal variation. Arsenic concentrations were analyzed using ordinary kriging for spatial interpolation, along with descriptive and inferential statistical methods. Human health risk was assessed through the following two key indicators: the Hazard Quotient (HQ), which estimates non-carcinogenic risk by comparing exposure levels to reference doses and carcinogenic risk (CR), which represents the estimated lifetime probability of developing cancer due to arsenic exposure. The mean arsenic concentration across both study years was 0.0200 mg/L, with median values of 0.0151 mg/L in 2015 and 0.0200 mg/L in 2020. The average HQ was 2.13 in 2015 and 2.17 in 2020, both exceeding the safety threshold of one. Mean CR values were 0.00096 and 0.00097 for 2015 and 2020, respectively, with a consistent median of 0.00072 across both years. A t-test was applied to compare the distributions between years. Both HQ and CR values significantly exceeded the recommended safety limits (p < 0.05), indicating that groundwater in the study area poses a potential carcinogenic and non-carcinogenic health risk. These findings underscore the urgent need for water quality monitoring and the implementation of mitigation measures to safeguard public health in the region. Full article

(This article belongs to the Special Issue Advances in Groundwater Resource Development: Innovative Methods and Technologies)

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18 pages, 3184 KB

Open AccessArticle

Changes in Macroinvertebrate Community Structure Associated with Land Use in Sierra Nevada de Santa Marta, Colombia

by Cristian Granados-Martínez, Meyer Guevara-Mora, Eugenia López-López and José Rincón Ramírez

Water 2025, 17(14), 2142; https://doi.org/10.3390/w17142142 - 18 Jul 2025

Viewed by 1246

Abstract

Rivers in tropical semi-arid regions face increasing anthropogenic pressures yet remain critically understudied despite their global importance. This study evaluated the aquatic macroinvertebrate community structure in the Ranchería River, Colombia, across three land use conditions: conserved zones (CZs), urban/agricultural zones (UAZs), and mining [...] Read more.

Rivers in tropical semi-arid regions face increasing anthropogenic pressures yet remain critically understudied despite their global importance. This study evaluated the aquatic macroinvertebrate community structure in the Ranchería River, Colombia, across three land use conditions: conserved zones (CZs), urban/agricultural zones (UAZs), and mining influence zones (MZs). Ten sampling stations were established, and macroinvertebrate communities were assessed alongside physical, chemical, and hydromorphological variables during the dry season (January–March 2021). A total of 9288 individuals from 84 genera across 16 orders were collected. Generalized Linear Models revealed significant differences among zones for 67 genera (79.8%), indicating strong community responses to land use gradients. Conserved zones exhibited the highest diversity according to the Hill numbers and were dominated by sensitive taxa, including Simulium, Smicridea, and Leptohyphes. Urban/agricultural zones showed the lowest richness (35 genera) and were characterized by disturbance-tolerant species, particularly Melanoides. Mining zones displayed intermediate diversity but exhibited severe habitat alterations. A redundancy analysis with variance partitioning revealed that land use types constituted the primary driver of community structure (a 24.1% pure effect), exceeding the physical and chemical variables (19.5%) and land cover characteristics (19.2%). The integrated model explained 63.5% of the total compositional variation, demonstrating that landscape-scale anthropogenic disturbances exert a greater influence on aquatic communities than local environmental conditions alone. Different anthropogenic activities create distinct environmental filters affecting macroinvertebrate assemblages, emphasizing the importance of land use planning for maintaining aquatic ecosystem integrity in semi-arid watersheds. Full article

(This article belongs to the Special Issue Biodiversity of Freshwater Ecosystems: Monitoring and Conservation, 2nd Edition)

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43 pages, 1241 KB

Open AccessReview

A Comprehensive Review of Agricultural Residue-Derived Bioadsorbents for Emerging Contaminant Removal

by Janaína Oliveira Gonçalves, André Rodríguez Leones, Bruna Silva de Farias, Mariele Dalmolin da Silva, Débora Pez Jaeschke, Sibele Santos Fernandes, Anelise Christ Ribeiro, Tito Roberto Santanna Cadaval, Jr. and Luiz Antonio de Almeida Pinto

Water 2025, 17(14), 2141; https://doi.org/10.3390/w17142141 - 18 Jul 2025

Viewed by 779

Abstract

The increasing presence of ECs in aquatic environments has drawn significant attention to the need for innovative, accessible, and sustainable solutions in wastewater treatment. This review provides a comprehensive overview of the use of agricultural residues—often discarded and undervalued—as raw materials for the [...] Read more.

The increasing presence of ECs in aquatic environments has drawn significant attention to the need for innovative, accessible, and sustainable solutions in wastewater treatment. This review provides a comprehensive overview of the use of agricultural residues—often discarded and undervalued—as raw materials for the development of efficient bioadsorbents. Based on a wide range of recent studies, this work presents various types of materials, such as rice husks, sugarcane bagasse, and açaí seeds, that can be transformed through thermal and chemical treatments into advanced bioadsorbents capable of removing pharmaceuticals, pesticides, dyes, and in some cases, even addressing highly persistent pollutants such as PFASs. The main objectives of this review are to (1) assess agricultural-residue-derived bioadsorbents for the removal of ECs; (2) examine physical and chemical modification techniques that enhance adsorption performance; (3) evaluate their scalability and applicability in real-world treatment systems. The review also highlights key adsorption mechanisms—such as π–π interactions, hydrogen bonding, and ion exchange—alongside the influence of parameters like pH and ionic strength. The review also explores the kinetic, isothermal, and thermodynamic aspects of the adsorption processes, highlighting both the efficiency and reusability potential of these materials. This work uniquely integrates microwave-assisted pyrolysis, magnetic functionalization, and hybrid systems, offering a roadmap for sustainable water remediation. Finally, comparative performance analyses, applications using real wastewater, regeneration strategies, and the integration of these bioadsorbents into continuous treatment systems are presented, reinforcing their promising role in advancing sustainable water remediation technologies. Full article

(This article belongs to the Special Issue Advanced Biotechnologies for Water and Wastewater Treatment, 2nd Edition)

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18 pages, 5708 KB

Open AccessArticle

Monitoring the Permeability and Evaluating the Impact of Cleaning on Two Permeable Pavement Systems

by Oscar Perez, Lu-Ming Chen, Jui-Wen Chen, Timothy J. Lecher, Lane A. Simpson, Ting-Hao Chen and Paul C. Davidson

Water 2025, 17(14), 2140; https://doi.org/10.3390/w17142140 - 18 Jul 2025

Viewed by 452

Abstract

Permeable pavement is an alternative to conventional impermeable pavement for various applications. However, a common issue with permeable pavement is clogging over time. Permeability is a parameter that reflects the capacity of the pavement to reduce surface runoff; a decline in permeability implies [...] Read more.

Permeable pavement is an alternative to conventional impermeable pavement for various applications. However, a common issue with permeable pavement is clogging over time. Permeability is a parameter that reflects the capacity of the pavement to reduce surface runoff; a decline in permeability implies the occurrence of clogging. In this study, permeability data collected on pervious concrete (PC) and JW Eco-Technology (JW) revealed that JW maintained consistent permeability over time. However, PC displayed reduced values, and several locations along the edges had zero permeability, despite no regular vehicular and pedestrian use. Therefore, a portable pressure washer was used to clean the pavements. The cleaning procedure was able to recover the permeability of the areas that showed signs of clogging (0 to 2.69 cm/s) and restore the permeability of PC up to 4.60–5.58 cm/s for corner and center areas, respectively. Moreover, visual inspection using a borescope further revealed the full function of the JW pores (aqueducts), regardless of cleaning. Regardless, it is recommended that periodic cleaning maintenance be performed for both PC and JW using a pressure washer due to its convenience and efficacy, which will be discussed. Full article

(This article belongs to the Special Issue Urban Water Management: Challenges and Prospects)

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32 pages, 1689 KB

Open AccessReview

Photocatalytic Degradation of Microplastics in Aquatic Environments: Materials, Mechanisms, Practical Challenges, and Future Perspectives

by Yelriza Yeszhan, Kalampyr Bexeitova, Samgat Yermekbayev, Zhexenbek Toktarbay, Jechan Lee, Ronny Berndtsson and Seitkhan Azat

Water 2025, 17(14), 2139; https://doi.org/10.3390/w17142139 - 18 Jul 2025

Viewed by 1099

Abstract

Due to its persistence and potential negative effects on ecosystems and human health, microplastic pollution in aquatic environments has become a major worldwide concern. Photocatalytic degradation is a sustainable manner to degrade microplastics to non-toxic by-products. In this review, comprehensive discussion focuses on [...] Read more.

Due to its persistence and potential negative effects on ecosystems and human health, microplastic pollution in aquatic environments has become a major worldwide concern. Photocatalytic degradation is a sustainable manner to degrade microplastics to non-toxic by-products. In this review, comprehensive discussion focuses on the synergistic effects of various photocatalytic materials including TiO₂, ZnO, WO₃, graphene oxide, and metal–organic frameworks for producing heterojunctions and involving multidimensional nanostructures. Such mechanisms can include the generation of reactive oxygen species and polymer chain scission, which can lead to microplastic breakdown and mineralization. The advancements of material modifications in the (nano)structure of photocatalysts, doping, and heterojunction formation methods to promote UV and visible light-driven photocatalytic activity is discussed in this paper. Reactor designs, operational parameters, and scalability for practical applications are also reviewed. Photocatalytic systems have shown a lot of development but are hampered by shortcomings which include a lack of complete mineralization and production of intermediary secondary products; variability in performance due to the fluctuation in the intensity of solar light, limited UV light, and environmental conditions such as weather and the diurnal cycle. Future research involving multifunctional, environmentally benign photocatalytic techniques—e.g., doped composites or composite-based catalysts that involve adsorption, photocatalysis, and magnetic retrieval—are proposed to focus on the mechanism of utilizing light effectively and the environmental safety, which are necessary for successful operational and industrial-scale remediation. Full article

(This article belongs to the Section Wastewater Treatment and Reuse)

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14 pages, 3236 KB

Open AccessArticle

Climate Change for Lakes in the Coterminous United States in Relation to Lake Warming from 1981 to 2023

by Roger W. Bachmann

Water 2025, 17(14), 2138; https://doi.org/10.3390/w17142138 - 18 Jul 2025

Viewed by 320

Abstract

The goal of this study was to look at changes in mean air temperatures, minimum air temperatures, maximum air temperatures, dew points, and precipitation over each of 1033 lakes in the coterminous United States over the summer months in the years 1981–2024. Near-surface [...] Read more.

The goal of this study was to look at changes in mean air temperatures, minimum air temperatures, maximum air temperatures, dew points, and precipitation over each of 1033 lakes in the coterminous United States over the summer months in the years 1981–2024. Near-surface water temperatures in the same lakes were calculated with equations using 8-day mean daily air temperatures, latitude, elevation, and the year of sampling. Over the past 43 years, there have been changes in air temperatures over many lakes of the United States with generally increasing trends for minimum air temperatures and mean air temperatures during the months of June through September. The greatest increases have been in daily minimum air temperatures followed by the mean daily air temperatures. Maximum daily air temperatures did not show a statistically significant increase for the summer season but did show a significant increase for the month of September. Along with the changes in the climate, the near-surface water temperatures of the lakes of the United States on average showed increases of 0.33 °C decade⁻¹ for the four summer months and increases for each of the summer months. Full article

(This article belongs to the Special Issue Impacts of Climate Change on Water Resources: Assessment and Modeling, 2nd Edition)

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24 pages, 2309 KB

Open AccessArticle

Technical and Economic Analysis of Strategies to Reduce Potable Water Consumption in a Library

by Caio Morelli Figueroba, Igor Catão Martins Vaz, Liseane Padilha Thives and Enedir Ghisi

Water 2025, 17(14), 2137; https://doi.org/10.3390/w17142137 - 18 Jul 2025

Viewed by 447

Abstract

In Brazil, approximately 93 trillion litres of water are withdrawn annually from surface and groundwater sources, with urban human use being the second-largest water consumer. Therefore, reducing water consumption in buildings is crucial. This study performed a technical and economic analysis of isolated [...] Read more.

In Brazil, approximately 93 trillion litres of water are withdrawn annually from surface and groundwater sources, with urban human use being the second-largest water consumer. Therefore, reducing water consumption in buildings is crucial. This study performed a technical and economic analysis of isolated and combined water-saving strategies at the Central Library of the Federal University of Santa Catarina (UFSC). The strategies assessed included water-saving appliances, rainwater harvesting, and greywater and blackwater reuse, individually and in four combined scenarios. User surveys provided data on the frequency and duration of water appliance use and cleaning activities, while on-site water flow measurements enabled the estimation of water end uses. The potential for potable water savings was then determined for each strategy and scenario. The highest savings (77.96%) were achieved by combining water-saving appliances with blackwater reuse, followed by a combination of water-saving appliances, greywater reuse, and rainwater harvesting (65.73%). All strategies were economically viable, except the combination of water-saving appliances with greywater reuse, which showed a negative net present value. The scenario combining water-saving appliances and blackwater reuse generated the most significant financial savings (R$7782.48 per month), with a payback period of 50 months. Given its environmental and economic benefits, these scenarios were recommended for implementation. The study may be replicated worldwide, and one key conclusion is that libraries consume a significant amount of potable water for non-potable purposes, which should be supplemented with alternative sources. It is essential to consider whether the building is already built or under design, as some implementation processes require design modifications. Full article

(This article belongs to the Section Urban Water Management)

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